Wednesday, October 24, 2012

The Limits of Lifestyle Intervention

Diet and exercise: they were supposed to be the answer to all that ails America's obesity and health care cost problem.

Signs of this Utopian vision are everywhere. From entire government departments encouraging healthy lifestyles through fitness, sports and nutrition, government websites that encourage "healthy lifestyles," and entire community efforts to partner with health care organizations to fight obesity with the hope of cutting health care costs.

What if, believe it or not, when it comes to people with Type II diabetes, diet and exercise don't affect the incidence of heart attack, stroke, or hospital admission for angina or even the incidence of death?

Suddenly, all health care cost savings bets are off. Suddenly, we have to re-tool, re-think our approach, understand and appreciate the limitation of lifestyle interventions to alter peoples' medical destiny. Suddenly we have to come to grips with a the reality that weight loss and exercise won't affect outcomes in certain patients. Suddenly, there is a sad reality that patients might note be able to affect their insurance premiums by enrolling in diet and exercise classes after all.

These thoughts are so disruptive to our most basic "healthy lifestyle" mantra that few can fathom such a situation. Nor would any members of the ever-beauty-and-weight-conscious main stream media be likely to report such a finding if it came to pass.

And yet, that is exactly what has happened.

The Look AHEAD trial studied 5145 adults with type 2 diabetes who had a body mass index (BMI) > 25. The purpose of the study was to compare the incidence of nonfatal myocardial infarction (heart attack), nonfatal stroke, death, or hospitalization for angina between diabetics who received a rigourous weight loss and exercise program with education to just an educational approach alone. Interestingly, the study failed to show any effect of weight loss and exercise over simple education about the disease in the incidence of these "macrovascular" endpoints. In fact, the study was stopped early.

So disturbing were these findings to our basic understanding of disease prevention that the principle investigator recently appeared on Medscape in print and in video format to reassure the physician community: "I can tell you from the outset that we were successful."

And yet, they were not: they did not affect the indicence of stroke, heart attack, death, or admission to a hospital for angina in overweight Type II diabetic patients one bit, even after 11 years of trying.

You see, it is uncomfortable to sit with the reality that exercise and fitness might not be as helpful as we had hoped at altering certain health care outcomes. So we ignore these trials. We don't report them in main stream media because we don't like to feel uncomfortable with the realization that there's much we still don't know or understand about exercise and weight loss at affecting health outcomes in medicine.

Yet there is so much to learn from trials like this BECAUSE they fly in the face of conventional wisdom.

Maybe we should stop pouring money into fitness rooms and health clubs and promote other intellectual or spiritual pursuits instead. Maybe we should reconsider the benefits of exercise and weight loss as psychologic more than physical. Maybe we should de-fund all those government programs set up to promote exercise and fitness as our path to health care cost-savings.

Or at the very least, we should just eat some humble pie, stop fooling ourselves, and understand the limitations of lifestyle interventions like weight loss and exercise to improve medical outcomes or to reduce health care costs in America.

I've seen this reported also. But it doesn't really matter. The damage has already been done. Everyone has bought into the idea that if you have a disease, it's your own fault. You should have eaten less and made your way to the tread mill. They aren't going to give up on that because if my cancer was beyond my control, you can't control whether or not you might get it. It's that simple.

Major employers have tiered their employee health benefit plans according to an employee's own health maintenance (the idea that it all is controllable if we eat right and exercise).

The cashier at my local grocery store told me she was worried because she went out to eat the night before for a birthday party forgetting she had blood work to be done to judge her personal health maintenance that next morning. Seems insurance renewal time is here and she was concerned one off number would cause her to have to pay a lot more for her health insurance. If this happened she would not be able to afford insurance anymore on her cashier's pay.

Common sense would tell us that one study does not change the general idea that a national agenda focused on healthy lifestyles could not benefit a lifelong campaign for increase in healthy outcomes.

Last time I was in Vienna, Budapest, Prague, Moscow, Berlin, I was careful to observe a wonderful transportation system based on light rail, convenience, and some walking. What would we do with something like that in Akron, Minneapolis, Indianapolis, etc.?

I imagined acres of greenhouses outside of Vienna, for winter garden production of spinach, tomatoes, and other greens.

And, German high schools that offered technical, and other hands-on training, instead of just this computer sit-on-your-butt crock of 'modern work ethic'.

I was the healthiest when I was 'forced' to walk or ride a bicycle for short-distance transportation, and carry my lunch in a paper sack, and drink only water from the water fountain. That was when I was a young married student year ago, too poor to work more than three part-time jobs at one time, and no health insurance, no visit to the dentist, nor new glasses.

Isn't against the law to tied employee health benefit plans to an arbitrary 'health maintenance insurance scheme. One would think this would be a 'pre-existing' condtion!!

Nowadays, the automobile runs until something breaks, then I work extra to pay for another at my sedentary job, riding the elevator instead of walking the three flights of stairs, and purchasing a 75 cents candy bar or Pop-Tart for breakfast when I get to work early instead of 75 cents bags of just as fat and salty peanuts and M&Ms.

Huh. Just stumbled onto this post while I was looking for info on differentiating AVRT from AVNRT (I'm an EM doc). Your post derailed me a little!

I'm not sure why your language is so strong, reacting to the Look AHEAD trial. Whatever the results of that trial, the cardiology literature is replete with studies that attest to the utility of exercise in both the primary prevention of heart disease, and the secondary treatment of CAD and heart failure, especially in the DM population.

Of course, lifestyle interventions are no panacea, but neither are statins. Heck, PCI for non-acute CAD is probably more controversial than lifestyle modification!

I agree that some of the public seems to view any aberration in their health (cancer, MI) as a personal and moral failing on their own part. Balderdash - there is so much chance and fate tied up with the date and quality of your death. Broccoli and jogging can only go so far.

Nonetheless, it would behoove us to eat our veggies and take a goddamn walk now and then!

Anyway, enough diversion; I'm going to keep looking for an EP blog that can help me with this set of interesting ECGs I ended up with after my last shift.

SYou are right about diet and exercise not being a panacea. Thank you very much for pointing out that illness is not a personal failure. Unfortunately almost no one else seems to appreciate that. Thus, the personal trainer at the new gym decided that my long qt syndrome was due to a lack of exercise anf my breast cancer was due to a poor diet. I can guarantee you that my diet is better than the protein bars and the power shakes that he consumes. Sadly though, he is far from the minority. And the idea that you can avoid all disease if you exercise enough and eat the approved diet is an easy sale, until it doesn't work.

Looking at the numberes in the study, it looks more like there so called intensive lifestyle intervention did not acheive very impressive results. Only a 6% change in body weight over 10 plus years? A 3 point reduction in systolic? Seems like medical intervention with anti-hypertensives and statins would blunt most of the parameters they monitored, so if they were still being treated with these medications and adjusted by their physicians, one might not expect to see a significant change as medical management will blunt any differences attributable to diet and exercise.

Even though the differences in the 2 groups are statistically significant, I think the raw data indicates there is not a significant difference in most of thee risk factors they measured. You would consequently expect that the differnece in the endpoints would also not be very significant.

Dr. Wes,I think you are overgeneralizing the results of this study..."Suddenly, all health care cost savings bets are off. Suddenly, we have to re-tool, re-think our approach, understand and appreciate the limitation of lifestyle interventions to alter peoples' medical destiny." All bets are off? No. Do we need to re-think our approach? Yes, but I do not think we need to eschew lifestyle intervention completely. I still think it is important to continue promoting healthy lifestyles and encouraging weight management, especially in a preventative capacity.

Let my explain my thinking. This study shows that intense lifestyle intervention for obese individuals with Type II Diabetes does not increase cardiovascular outcomes. However, the study did show benefits for these patients in many other aspects of their health. Furthermore, although differences between the lifestyle intervention group and the controls were statistically significant, the lifestyle intervention group was only able to maintain a 6.2% weight loss by year 4 of the study (the one you provide as a reference in your post). For an individual starting the study at 300 lbs, this would only be an 18 lb loss. That's not a lot of weight loss. Would we see improved cardiovascular outcome if people could lose more weight? 10%, 20%, 30% weight reduction. Perhaps...

The biggest failure of this study is that the lifestyle interventions did not go far enough. The participants just weren't able to make enough gains in their health to see a cardiovascular benefit. We fail (as a society, as individuals, as healthcare providers) to understand how to get people back down to healthier weights and lower % body fat in an effective manner. Once we figure this out, perhaps we will indeed be able to decrease the risk heart attack, stroke, and death in these individuals.

But what if a more effective lifestyle intervention didn't work? What if we didn't see improved outcomes for people even if they were to lose even more weight? Perhaps becoming obese and developing Type II diabetes starts this Rube-Goldberg-like disease process that once initiated you are destined for a heart attack? If this is indeed the case, then the emphasis should still be on prevention. Let's encourage people from building that Rube-Goldberg machine in the first place. Let's promote healthy lifestyles and weights before people get to the obese, Type II diabetes stage.

Don't use the results of this study to discourage the use of lifestyle interventions in people who still have a chance to see a benefit from it. Nor should you discourage people who are at a more difficult stage from trying lifestyle intervention, even if it is only for the other health benefits described in this study.

The findings of the study are not really surprising as tight control of diabetes has previously been shown to have little effect on preventing macrovascular events. Does not mean that exercise is not beneficial for other problems and in non diabetics.

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About Me

Westby G. Fisher, MD, FACC is a board certified internist, cardiologist, and cardiac electrophysiologist (doctor specializing in heart rhythm disorders) practicing at NorthShore University HealthSystem in Evanston, IL, USA and is a Clinical Associate Professor of Medicine at University of Chicago's Pritzker School of Medicine. He entered the blog-o-sphere in November, 2005.
DISCLAIMER: The opinions expressed in this blog are strictly the those of the author(s) and should not be construed as the opinion(s) or policy(ies) of NorthShore University HealthSystem, nor recommendations for your care or anyone else's. Please seek professional guidance instead.